The Rule of St. Benedict

If a brother hath often been corrected and hath even been excommunicated for a fault and doth not amend, let a more severe correction be applied to him, namely, proceed against him with corporal punishment.

But if even then he doth not reform, or puffed up with pride, should perhaps, which God forbid, even defend his actions, then let the Abbot act like a prudent physician. After he hath applied soothing lotions, ointments of admonitions, medicaments of the Holy Scriptures, and if, as a last resource, he hath employed the caustic of excommunication and the blows of the lash, and seeth that even then his pains are of no avail, let him apply for that brother also what is more potent than all these measures: his own prayer and that of the brethren, that the Lord who is all-powerful may work a cure in that brother.

But if he is not healed even in this way, then finally let the Abbot dismiss him from the community, as the Apostle saith: "Put away the evil one from among you" (1 Cor 5:13); and again: "If the faithless depart, let him depart" (1 Cor 7:15); lest one diseased sheep infect the whole flock.